/**
 * Copyright (C) 2013 Open Whisper Systems
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.appspot.eusms;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ProgressBar;

import com.appspot.eusms.crypto.DecryptingQueue;
import com.appspot.eusms.crypto.IdentityKeyUtil;
import com.appspot.eusms.database.DatabaseFactory;
import com.appspot.eusms.notifications.MessageNotifier;
import com.appspot.eusms.util.VersionTracker;

import com.appspot.eusms.R;

import org.whispersystems.textsecure.crypto.MasterSecret;

import java.util.SortedSet;
import java.util.TreeSet;

public class DatabaseUpgradeActivity extends Activity {

    public static final int NO_MORE_KEY_EXCHANGE_PREFIX_VERSION = 46;
    public static final int MMS_BODY_VERSION = 46;
    public static final int TOFU_IDENTITIES_VERSION = 50;
    public static final int CURVE25519_VERSION = 63;

    private static final SortedSet<Integer> UPGRADE_VERSIONS = new TreeSet<Integer>() {{
        add(NO_MORE_KEY_EXCHANGE_PREFIX_VERSION);
        add(TOFU_IDENTITIES_VERSION);
        add(CURVE25519_VERSION);
    }};

    private MasterSecret masterSecret;

    @Override
    public void onCreate(Bundle bundle) {
        super.onCreate(bundle);
        this.masterSecret = getIntent().getParcelableExtra("master_secret");

        if (needsUpgradeTask()) {
            Log.w("DatabaseUpgradeActivity", "Upgrading...");
            setContentView(R.layout.database_upgrade_activity);

            ProgressBar indeterminateProgress = (ProgressBar) findViewById(R.id.indeterminate_progress);
            ProgressBar determinateProgress = (ProgressBar) findViewById(R.id.determinate_progress);

            new DatabaseUpgradeTask(indeterminateProgress, determinateProgress)
                    .execute(VersionTracker.getLastSeenVersion(this));
        } else {
            VersionTracker.updateLastSeenVersion(this);
            DecryptingQueue.schedulePendingDecrypts(DatabaseUpgradeActivity.this, masterSecret);
            MessageNotifier.updateNotification(DatabaseUpgradeActivity.this, masterSecret);
            startActivity((Intent) getIntent().getParcelableExtra("next_intent"));
            finish();
        }
    }

    private boolean needsUpgradeTask() {
        try {
            int currentVersionCode = getPackageManager().getPackageInfo(getPackageName(), 0).versionCode;
            int lastSeenVersion = VersionTracker.getLastSeenVersion(this);

            Log.w("DatabaseUpgradeActivity", "LastSeenVersion: " + lastSeenVersion);

            if (lastSeenVersion >= currentVersionCode)
                return false;

            for (int version : UPGRADE_VERSIONS) {
                Log.w("DatabaseUpgradeActivity", "Comparing: " + version);
                if (lastSeenVersion < version)
                    return true;
            }

            return false;
        } catch (PackageManager.NameNotFoundException e) {
            throw new AssertionError(e);
        }
    }

    public static boolean isUpdate(Context context) {
        try {
            int currentVersionCode = context.getPackageManager().getPackageInfo(context.getPackageName(), 0).versionCode;
            int previousVersionCode = VersionTracker.getLastSeenVersion(context);

            return previousVersionCode < currentVersionCode;
        } catch (PackageManager.NameNotFoundException e) {
            throw new AssertionError(e);
        }
    }

    public interface DatabaseUpgradeListener {
        public void setProgress(int progress, int total);
    }

    private class DatabaseUpgradeTask extends AsyncTask<Integer, Double, Void>
            implements DatabaseUpgradeListener {

        private final ProgressBar indeterminateProgress;
        private final ProgressBar determinateProgress;

        public DatabaseUpgradeTask(ProgressBar indeterminateProgress, ProgressBar determinateProgress) {
            this.indeterminateProgress = indeterminateProgress;
            this.determinateProgress = determinateProgress;
        }

        @Override
        protected Void doInBackground(Integer... params) {
            Context context = DatabaseUpgradeActivity.this.getApplicationContext();

            Log.w("DatabaseUpgradeActivity", "Running background upgrade..");
            DatabaseFactory.getInstance(DatabaseUpgradeActivity.this)
                    .onApplicationLevelUpgrade(context, masterSecret, params[0], this);

            if (params[0] < CURVE25519_VERSION) {
                if (!IdentityKeyUtil.hasCurve25519IdentityKeys(context)) {
                    IdentityKeyUtil.generateCurve25519IdentityKeys(context, masterSecret);
                }
            }

            return null;
        }

        @Override
        protected void onProgressUpdate(Double... update) {
            indeterminateProgress.setVisibility(View.GONE);
            determinateProgress.setVisibility(View.VISIBLE);

            double scaler = update[0];
            determinateProgress.setProgress((int) Math.floor(determinateProgress.getMax() * scaler));
        }

        @Override
        protected void onPostExecute(Void result) {
            VersionTracker.updateLastSeenVersion(DatabaseUpgradeActivity.this);
            DecryptingQueue.schedulePendingDecrypts(DatabaseUpgradeActivity.this, masterSecret);
            MessageNotifier.updateNotification(DatabaseUpgradeActivity.this, masterSecret);

            startActivity((Intent) getIntent().getParcelableExtra("next_intent"));
            finish();
        }

        @Override
        public void setProgress(int progress, int total) {
            publishProgress(((double) progress / (double) total));
        }
    }

}
